Presumably they have six weeks of leave in the year as part of their contract, and this man is prepared to lose one of these to retain his pension rights. "Option days" must be linked to leave in some way. Again, something within the employment contract.
"They must be screwed over..." = a slang term for time-wasting in this context.
"my 401" = A 401(k) plan is a retirement savings plan that is funded by employee contributions and (often) matching contributions from the employer. So this man is saying let him have a lump sum so that he can take retirement immediately.
Student or Learner